As well known to those skilled in the art, an internal combustion engine for automobiles is typically and separately provided with two types of sensors, that is, a MAP (manifold absolute pressure) sensor and a temperature sensor. The MAP sensor is used for auxiliarily controlling suction timing of mixed gas into a cylinder by sensing the internal pressure of a surge tank and outputting a pressure signal to an ECU (electronic control unit) for the engine. Meanwhile, the temperature sensor is used for sensing the temperature of inlet air, which is sucked into the cylinder through an air cleaner, prior to outputting a temperature signal to the ECU. The temperature sensor thus allows the ECU to effectively calculate an appropriate amount of air for the engine in accordance with a density variation of air caused by the variable temperature. The MAP sensor is installed in a surge tank of an engine, while the temperature sensor is installed in an intake tube. However, the two sensors are designed to perform different functions and are separately mounted to their positions in an engine, thus having the following problems.
1. The conventional MAP and temperature sensors are separately positioned in an engine, thus complicating the construction of the engine and consuming labor and time and reducing work efficiency while being installed in the engine.
2. The temperature sensor, which is installed in the intake tube of the engine, is regrettably exposed to impurities such as moisture, dust and powdered rock in the inlet air and so such impurities easily damage the temperature sensor and reduce the sensitivity of the sensor, thereby reducing the operational precision of the temperature sensor.
3. The separately mounted MAP and temperature sensors increase the numbers of parts of the sensors, thus lengthening the processing time, reducing productivity and increasing the production cost.